No causative studies has ever shown artificial sweeteners causing weight gain.

没有任何研究表明人造甜味剂会导致体重增加。

However, in about 40% to 25% of the cases the causative genes are still unknown.

是，有40％至25％病例的致病基因仍然未知。

Maybe you noticed this structure is called the causative.

也许你注意到这个结构被称为使役。

In this lesson, we're looking at causative verbs.

本节，要学习使役动词。

When we want to talk about that, we use causative verbs.

当想谈论这个问题时，使用使役动词。

There are more than 10 causative verbs in English.

英语中有 10 多个使役动词。

Right, let's get started with the causative verbs.

好的，开始讲解使役动词。

Let's look at another causative verb — have.

来看看另一个使役动词 have。

We are going to be talking about causative verbs, in particular, have, make, get, help and let.

将讨论释义动词，特别是 have，make，get，help 和 let。

As I said before, we're looking at five verbs that we use with causative structures.

就像之前说的那样，要学习五个使用使役结构的动词。

The causative verb or the other verb?

使役动词还是另一个动词？

It's the causative verb that takes the tense.

使用时态的是使役动词。

Now there are two ways that we can use have as a causative verb.

使用 have 作为使役动词有两种方式。

It's about the causative verbs 'have' and 'get'.

内容关于使役动词 have 和 get。

Now you know the meanings of the three most common causative verbs.

现在你知道了三个最常见的使役动词的意思了。

In Africa, we experience more than 140 outbreaks every year: viral outbreaks, bacterial outbreaks, or outbreaks of unknown causative agent.

在非洲，每年历 140 多起疫情：病毒疫情、细菌疫情或未知病原体疫情。

Now, I get asked many times how to construct and use the causative structure.

现在，多次被问及如何构建和使用使役结构。

First of all, " What is the causative" , you're wondering?

首先，“原因是什么”，您想知道吗？

So this could be COVID-19 a vaccine against SARS-coronavirus-2, SARS-CoV-2, the causative agent of COVID-19.

所以这可能是 COVID-19，一种针对 SARS-coronavirus-2、SARS-CoV-2 的疫苗，SARS-CoV-2 是 COVID-19 的病原体。

Some are in the causative structure; some are not in the causative structure.

有些在使役结构中；有些不在使役结构中。